2018 · Q29
A cyclist covers his first 20 km at an average speed of 40 kmph, another 10 km at an average speed of 10 kmph and the last 30 km at an average speed of 40 kmph. Then the average speed of the entire journey is
Elementary MathematicsTime, Speed and Distance
- A20 kmph
- B26.67 kmph
- C28.24 kmph
- D30 kmph
Explanation
Total time = 20/40 + 10/10 + 30/40 = 0.5 + 1 + 0.75 = 2.25 hours for 60 km. Average speed = 60/2.25 = 26.67 kmph. Hence option B.